Breathing circuits may comprise a number of respiratory tubes which are connected together to form a primary gases passageway. Secondary devices may need to be connected to the primary gases passageway, for example via ports in the side wall thereof. The various parts of the circuit are typically connected by connectors having standard fittings to allow male or female tube fittings to be connected thereto.
It is desirable to be able to change the relative orientations of the connected parts in a number of situations. For example, in the case where a connected secondary device includes an elongate element such as a tube, the elongate element may interfere with the work of the clinician during treatment of the patient. There exist a number of other scenarios in which it may be desirable to reorient connected tubing or devices, such as to prevent interference with a view of, or access to, further components of the system or other equipment. It may therefore be advantageous to re-orientate one or more connected member relative to the primary gases passageway so that the elongate element no longer interferes.
If standard connectors are used, changing the orientation of one part relative to another typically requires the part to be disconnected from the circuit and reconnected in a different orientation. Thus standard connectors typically only allow relative rotation between the components when disconnected or else during connection, but not when the desired secure connection has been achieved. This process of disconnection and reconnection allows unwanted atmospheric gases into the circuit. Also, the twisting and reconnection of tubes, for example with a friction fit, introduces residual stress in the system which can potentially lead to loosening of the connection or else kinking within a tube, thereby restricting flow along the tube.
Existing rotating connectors, commonly referred to as “swivel” connectors, typically comprise two tubular conduits connected together and which are able to rotate relative to each other. FIG. 1 shows a prior art swivel connector. This shows a connector comprising an open connector end 101 of a first tube 102 received within an annular recess 103 located in the side wall of a second tube 104.
The annular recess encloses the connector end 101 of first tube 102 such that the desired relative positioning is achieved and a projection 105 on the connector end 101 maintains the end within annular recess 103. A plurality of circumferentially spaced abutments (not shown in FIG. 1) depend inwardly from the inwardly facing wall 106 of the second tube 104 at its open end in order to prevent removal of the connector end 101 from the annular recess 103.
Connectors of the type shown in FIG. 1 have been found to be inadequate for the purpose for re-orientating a component of a circuit such that it remains in a position in which it does not interfere with the treatment of a patient by a clinician. That is to say, any residual stress in the connected second tube 104, after re-orientation, will cause the tube 104 to return to its previous position, thereby requiring the connected tube to be moved repeatedly to its desired location, which can be both a distraction and an annoyance to the operator or clinician.
It has been found that the connector of the type shown in FIG. 1 can become disconnected. Thus, whilst the connector can prevent the connector end 101 being removed from the annular recess in normal use, there exists the possibility that the end could accidentally become disconnected upon application of sufficient tension to second tube 104 or else a bending moment about the connection.
Furthermore, whilst the connector arrangement of FIG. 1 is suitable for some simple types of connectors, such as elbow connectors or the like, the connector may not be suitable for other scenarios, such as, for example, when a secondary device is connected to the main gas passageway via the connector.